Senior Fullstack Developer .NET + React

We are looking for a Senior Fullstack Developer (.NET + React) to join a new project focused on developing modern solutions for the financial services sector. The role is approximately 70% backend and 30% frontend, involving C#/.NET, React 18+, T-SQL, microservices, DDD, Clean Code and SOLID. You will develop new functionalities, work with existing and legacy code, contribute to solution architecture, and collaborate with Developers, Testers, Analysts and the Product Owner in a Scrum environment.

Responsibilities

• Development in C# / .NET
• Frontend development in React
• Analysis and development of existing and legacy code
• Solution architecture
• Debugging, profiling and performance analysis
• Development of new functionality
• Work with TSQL and relational databases
• Cooperation with Developers, Testers, Analysts and Product Owner
• Work within Scrum Requirements
• Minimum 5 years commercial .NET development
• Minimum 3 years commercial React development
• Strong C#
• .NET Framework / .NET Standard / .NET Core / modern .NET
• React 18+
• TSQL
• Debugging and profiling
• Performance analysis
• DDD
• Clean Code
• SOLID
• Architectural patterns
• Asynchronous communication
• SQL Management Studio
• Visual Studio
• Fluent Polish
• English minimum B2 Nice to have
• Financial services / banking experience
• Mobile application views
• Automated testing
• Postman
• Playwright
• WCAG Benefits
• Flexible hybrid work model (1 day/week on-site in Warsaw/Gdańsk)
• Solid, competitive salary
• Work in a multinational environment on international projects
• Comprehensive healthcare
• Long-term B2B contract with a stable project pipeline